MOLPRO

19 THE MCSCF PROGRAM MULTI 140
19.6.2 Selecting the orbital optimization method
The ITERATIONS directive can be use to modify the defaults for the optimization method. It
consists of a sequence of several cards, which should be enclosed in a pair of curly brackets.
{ ITERATIONS;
DO,method1,iter1[,TO,iter2];
DONT,method2,iter3[,TO,iter4];
...
}
method can be one of the following:
DIAGCI
INTERNAL
WERNER
AUGMENT
NEWTON
UNCOUPLE
NULL
Diagonalize hamiltonian in the beginning of the specified iterations.
This is the default for iteration 1.
Optimize internal orbitals at the beginning of the specified iterations.
This is default for second and subsequent iterations.
use Werner-Meyer-Knowles non-linear optimization method for
the specified iterations. This is the default for all iterations.
Use step-restricted Augmented Hessian method for the specified
iterations.
Use Newton-Raphson method for specified iterations.
Do not optimize orbitals and CI coefficients simultaneously in
the specified iterations. This option will set DIAGCI for these
iterations.
No orbital optimization.
19.6.3 Disabling the optimization
In addition to the ITERATIONS directive described above, some procedures can be be disabled
more simply using the DONT directive. DONT,code
code may be
ORBITAL
WAVEFUNC
WVFN
ANAL
Do initial CI but don’t optimize orbitals.
Do not optimize the orbitals and CI coefficients (i.e. do only
wavefunction analysis, provided the orbitals and CI coefficients
are supplied (see START card)).
Alias for WAVEFUNC.
Do no wavefunction analysis.
19.6.4 Disabling the extra symmetry mechanism
NOEXTRA
This card disables the search for extra symmetries. By default, if extra symmetries are present,
each orbital is assigned to such an extra symmetry and rotations between orbitals of different
extra symmetry are not performed.